dns.vlt81.de has no MX records.
Question and response
Question
dig dns.vlt81.de. MX
Answer
The response has no answer records.
Authority
vlt81.de. 1200 SOA dns.vlt81.de. admin.vault81.de. 2026010511 1200 300 1209 1200900
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0